CVE-2026-3241
Stored XSS in Concrete CMS Legacy Form Allows Persistent Injection
Publication date: 2026-03-04
Last updated on: 2026-03-04
Assigner: ConcreteCMS
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| concretecms | concrete_cms | to 9.4.8 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-79 | The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability is a stored cross-site scripting (XSS) issue found in Concrete CMS versions below 9.4.8, specifically in the "Legacy Form" block.
An authenticated user who has permissions to create or edit forms, such as a rogue administrator, can inject persistent JavaScript code into the options of multiple-choice questions like Checkbox List, Radio Buttons, or Select Box.
When other users view the page containing the affected form, the injected JavaScript payload executes in their browsers, potentially leading to malicious actions.
How can this vulnerability impact me? :
This vulnerability can impact you by allowing an attacker with form editing permissions to execute malicious JavaScript in the browsers of users who view the compromised form.
Such execution can lead to unauthorized actions like stealing session cookies, defacing content, or performing actions on behalf of the victim user.
Because the attacker needs authenticated access with form editing rights, the risk is somewhat limited to insider threats or compromised administrator accounts.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
I don't know
What immediate steps should I take to mitigate this vulnerability?
I don't know